Experimental generation of optical Schrödinger cats from photon number states
Alexei Ourjoumtsev, Hyunseok Jeong, Rosa Tualle-Brouri, Philippe Grangier · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
A "Schrödinger cat" state of free-propagating light can be defined as a quantum superposition of well separated coherent states. 1, 2 We demonstrated, theoretically and experimentally, a protocol which allows to generate arbitrarily large squeezed Schrödinger cat states, using a homodyne detection and photon number states as resources. We implemented this protocol experimentally with light pulses containing two photons, producing a squeezed Schrödinger cat state with a negative Wigner function. This state clearly presents several quantum phase-space interference fringes between the "dead" and "alive" components, and it is large enough to become useful for experimental tests of quantum theory and quantum information processing.